Impact of the German nuclear phase-out on Europeʹs electricity generation—A comprehensive study

The combination of the ambitious German greenhouse gas reduction goals in the power sector and the nuclear phase-out raises many questions concerning the operational security of the German electricity generation system. This paper focusses on the technical feasibility (electricity generation and transmission) and CO2-impact of the German nuclear phase-out on the short term (2012–2022). A detailed electricity generation simulation model is employed, including the German transmission grid and its international connections. A range of different conventional and renewable energy sources (RES) scenarios is considered. Results are presented for the change in generation mix, on the flows on the transmission network and on operational reliability issues. The scenario analysis shows that nuclear generation will be replaced mainly by coal- and lignite-based generation. This increases the CO2-intensity of the German electricity sector. Furthermore, the results indicate that the German electricity export will decrease and under certain circumstances, the system becomes infeasible. Keeping some nuclear power plants online, would mitigate these effects. The amount of electricity generated from RES is shown to be the main driver for grid congestion.